From: Roberto Bergantinos Corpas <rbergant@redhat.com> stable inclusion from stable-v6.18.19 commit 203c792cb4315360d49973ae2e57feeb6d3dcf7e category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/8774 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 410666a298c34ebd57256fde6b24c96bd23059a2 ] If we found an alias through nfs3_do_create/nfs_add_or_obtain /d_splice_alias which happens to be a dir dentry, we don't return any error, and simply forget about this alias, but the original dentry we were adding and passed as parameter remains negative. This later causes an oops on nfs_atomic_open_v23/finish_open since we supply a negative dentry to do_dentry_open. This has been observed running lustre-racer, where dirs and files are created/removed concurrently with the same name and O_EXCL is not used to open files (frequent file redirection). While d_splice_alias typically returns a directory alias or NULL, we explicitly check d_is_dir() to ensure that we don't attempt to perform file operations (like finish_open) on a directory inode, which triggers the observed oops. Fixes: 7c6c5249f061 ("NFS: add atomic_open for NFSv3 to handle O_TRUNC correctly.") Reviewed-by: Olga Kornievskaia <okorniev@redhat.com> Reviewed-by: Scott Mayhew <smayhew@redhat.com> Signed-off-by: Roberto Bergantinos Corpas <rbergant@redhat.com> Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zizhi Wo <wozizhi@huawei.com> --- fs/nfs/nfs3proc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c index d84016e5346e..09eed676cb66 100644 --- a/fs/nfs/nfs3proc.c +++ b/fs/nfs/nfs3proc.c @@ -393,8 +393,13 @@ nfs3_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr, if (status != 0) goto out_release_acls; - if (d_alias) + if (d_alias) { + if (d_is_dir(d_alias)) { + status = -EISDIR; + goto out_dput; + } dentry = d_alias; + } /* When we created the file with exclusive semantics, make * sure we set the attributes afterwards. */ -- 2.39.2